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CastCheck methodology v0.2 · data through 2026-08-30

Seattle-Tacoma · ECMWF IFS HRES · lead day 0

KSEA · ifs_hres · lead 0

Target day = initialization date + 0 days. This page is a permanent link: the numbers change as history accumulates, the address and the methodology version do not.

Scores use the latest model version segment, ifs-gpid161, starting 2026-08-01 — days before that ran a different version of the model and are excluded rather than silently pooled. Of the scored days, 1 carry a QC flag on the observation.

JSON for this page CSV of the daily errors Cite this page

Every number for this combination

All four windows × both initializations × both interpolations × both variables. Errors are computed in °C and shown in °F; CI is a 95 % moving-block bootstrap interval. MAE debiased and skill, debiased remove the constant offset of the window first, so a station that the model always reads a degree too warm is not scored as if it had no skill — compare the two skill columns to see how much of the error is a fixed offset. n QC next to n counts days whose observation carries a QC flag.

VariableInitMethod Windown MAE °F MAE debiased Bias °F RMSE °F ±1 °F±2 °F±3 °F Skill Skill, debiased Period
tmax00Zbilinear30d25 1 QC1.78 [1.39, 2.11]1.59-0.85 [-1.61, -0.02]2.20 [1.68, 2.57]28% [13%, 43%]64%80%——2026-08-01 → 2026-08-30
tmax00Zbilinear90d25 1 QC1.78 [1.27, 2.11]1.59-0.85 [-1.72, 0.01]2.20 [1.58, 2.57]28% [9%, 50%]64%80%——2026-08-01 → 2026-08-30
tmax00Zbilinear365d25 1 QC1.78 [1.28, 2.10]1.59-0.85 [-1.69, 0.04]2.20 [1.58, 2.56]28% [7%, 50%]64%80%——2026-08-01 → 2026-08-30
tmax00Zbilinearall25 1 QC1.78 [1.25, 2.10]1.59-0.85 [-1.73, 0.02]2.20 [1.56, 2.56]28% [9%, 50%]64%80%——2026-08-01 → 2026-08-30
tmax00Znearest30d25 1 QC1.87 [1.49, 2.21]1.65-1.04 [-1.83, -0.20]2.38 [1.86, 2.82]36% [24%, 48%]60%80%——2026-08-01 → 2026-08-30
tmax00Znearest90d25 1 QC1.87 [1.36, 2.21]1.65-1.04 [-1.91, -0.17]2.38 [1.75, 2.81]36% [20%, 53%]60%80%——2026-08-01 → 2026-08-30
tmax00Znearest365d25 1 QC1.87 [1.38, 2.21]1.65-1.04 [-1.92, -0.14]2.38 [1.75, 2.80]36% [16%, 55%]60%80%——2026-08-01 → 2026-08-30
tmax00Znearestall25 1 QC1.87 [1.38, 2.20]1.65-1.04 [-1.93, -0.13]2.38 [1.77, 2.80]36% [20%, 54%]60%80%——2026-08-01 → 2026-08-30
tmin00Zbilinear30d25 1 QC1.85 [1.28, 2.41]1.01+1.67 [0.88, 2.39]2.14 [1.48, 2.61]28% [10%, 46%]56%84%——2026-08-01 → 2026-08-30
tmin00Zbilinear90d25 1 QC1.85 [1.21, 2.43]1.01+1.67 [0.67, 2.41]2.14 [1.39, 2.64]28% [6%, 48%]56%84%——2026-08-01 → 2026-08-30
tmin00Zbilinear365d25 1 QC1.85 [1.16, 2.45]1.01+1.67 [0.60, 2.43]2.14 [1.35, 2.64]28% [5%, 50%]56%84%——2026-08-01 → 2026-08-30
tmin00Zbilinearall25 1 QC1.85 [1.14, 2.47]1.01+1.67 [0.55, 2.44]2.14 [1.31, 2.65]28% [0%, 50%]56%84%——2026-08-01 → 2026-08-30
tmin00Znearest30d25 1 QC2.32 [1.61, 3.04]1.11+2.17 [1.30, 2.99]2.62 [1.84, 3.24]16% [0%, 33%]48%68%——2026-08-01 → 2026-08-30
tmin00Znearest90d25 1 QC2.32 [1.48, 3.08]1.11+2.17 [1.09, 3.08]2.62 [1.71, 3.28]16% [0%, 33%]48%68%——2026-08-01 → 2026-08-30
tmin00Znearest365d25 1 QC2.32 [1.44, 3.09]1.11+2.17 [1.05, 3.08]2.62 [1.68, 3.28]16% [0%, 36%]48%68%——2026-08-01 → 2026-08-30
tmin00Znearestall25 1 QC2.32 [1.42, 3.12]1.11+2.17 [1.03, 3.10]2.62 [1.62, 3.31]16% [0%, 36%]48%68%——2026-08-01 → 2026-08-30

+ model too warm · − model too cold · bias interval includes zero · ★ lowest MAE · = not distinguishable from the leader · ▼ significantly worse · n < 30 greyed and unranked · CI is a 95 % moving-block bootstrap interval.

Daily error, last 90 days

Daily forecast minus observed error in °F for ECMWF IFS HRES at KSEA, lead day 0, 00Z bilinear tmax+5+2.50-2.5-52026-08-01: -0.33 °F2026-08-06: -2.23 °F2026-08-08: -0.15 °F2026-08-09: +0.29 °F2026-08-10: +2.29 °F2026-08-11: -1.1 °F2026-08-12: -3.48 °F2026-08-13: +0.35 °F2026-08-14: +2.86 °F2026-08-15: +3.35 °F2026-08-16: -0.12 °F2026-08-17: -1.8 °F2026-08-18: -0.53 °F2026-08-19: -3.01 °F2026-08-20: -4.43 °F2026-08-21: +0.84 °F2026-08-22: -1.15 °F2026-08-23: -1.05 °F2026-08-24: -4.9 °F2026-08-25: -1.63 °F2026-08-26: +1.66 °F2026-08-27: -1.68 °F2026-08-28: -1.73 °F2026-08-29: -1.23 °F2026-08-30: -2.29 °F2026-08-012026-08-30°F, forecast − observed
Forecast − observed, °F, 00Z bilinear daily maximum. The dashed line is zero; the thick line is a centred 7-day mean, drawn only where the whole window is present. Gaps are days with no score, never interpolation. Hover a point for its date and value.
The same series as a table (30 days, newest first) · download CSV
Climatological dayError °F
2026-08-30-2.29
2026-08-29-1.23
2026-08-28-1.73
2026-08-27-1.68
2026-08-26+1.66
2026-08-25-1.63
2026-08-24-4.90
2026-08-23-1.05
2026-08-22-1.15
2026-08-21+0.84
2026-08-20-4.43
2026-08-19-3.01
2026-08-18-0.53
2026-08-17-1.80
2026-08-16-0.12
2026-08-15+3.35
2026-08-14+2.86
2026-08-13+0.35
2026-08-12-3.48
2026-08-11-1.10
2026-08-10+2.29
2026-08-09+0.29
2026-08-08-0.15
2026-08-07—
2026-08-06-2.23
2026-08-05—
2026-08-04—
2026-08-03—
2026-08-02—
2026-08-01-0.33

Error distribution

Distribution of the signed daily error in °F for ECMWF IFS HRES at KSEA, lead day 0-5 to -4.5 °F: 1 day-4.5 to -4 °F: 1 day-4 to -3.5 °F: 0 days-3.5 to -3 °F: 2 days-3 to -2.5 °F: 0 days-2.5 to -2 °F: 2 days-2 to -1.5 °F: 4 days-1.5 to -1 °F: 4 days-1 to -0.5 °F: 1 day-0.5 to 0 °F: 3 days0 to 0.5 °F: 2 days0.5 to 1 °F: 1 day1 to 1.5 °F: 0 days1.5 to 2 °F: 1 day2 to 2.5 °F: 1 day2.5 to 3 °F: 1 day3 to 3.5 °F: 1 day3.5 to 4 °F: 0 days4 to 4.5 °F: 0 days4.5 to 5 °F: 0 daysdashed: P50 |e| 1.66 · P90 |e| 3.43 °F-50+5 °Fn = 25 days
All scored days for 00Z bilinear daily maximum, 20 equal bins. The dashed marks are the 50th and 90th percentiles of the absolute error, mirrored on both sides. Hover a bar for its bin and count.
Bin counts as a table
From °FTo °FDays
-5.00-4.501
-4.50-4.001
-4.00-3.500
-3.50-3.002
-3.00-2.500
-2.50-2.002
-2.00-1.504
-1.50-1.004
-1.00-0.501
-0.50+0.003
+0.00+0.502
+0.50+1.001
+1.00+1.500
+1.50+2.001
+2.00+2.501
+2.50+3.001
+3.00+3.501
+3.50+4.000
+4.00+4.500
+4.50+5.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08251.78 -0.85

Availability

ModelScored period DaysCoverage
ECMWF IFS HRES2026-08-01 → 2026-08-30 25
ECMWF IFS HRES2026-08-01 → 2026-08-30 25

Compared with other models

Paired bootstrap on the days both models cover (90d, 00Z, bilinear, daily maximum). Negative means ECMWF IFS HRES has the lower MAE. "Distinguishable" means the 95 % interval excludes zero.

Other modelCommon days MAE difference °FDistinguishable
ECMWF AIFS Single 25 -4.15 [-5.22, -3.05] yes
Aurora (GFS init) 2 -3.34 [-5.41, -1.26] yes
Aurora (IFS init) 3 -1.58 [-2.55, 0.37] no
FourCastNet v2 (GFS init) 2 -1.96 [-5.15, 1.23] no
FourCastNet v2 (IFS init) 3 -0.41 [-1.68, 2.14] no
NCEP GFS 25 -2.05 [-3.56, -0.45] yes
GraphCast (GFS init) 2 -4.36 [-6.82, -1.90] yes
GraphCast (IFS init) 23 -2.53 [-3.19, -1.80] yes
Pangu-Weather (GFS init) 2 -2.02 [-2.73, -1.31] yes
Pangu-Weather (IFS init) 3 -0.03 [-0.71, 1.32] no

Cite this page

ShortCastCheck, KSEA ifs_hres lead 0, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KSEA/model/ifs_hres/lead/0/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KSEA (Seattle-Tacoma), model ifs_hres, lead day 0. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/KSEA/model/ifs_hres/lead/0/

Accessed2026-08-31 (data through 2026-08-30; page built 2026-08-31T03:52:06+00:00)

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